There is a considerable amount of expertise and technology used to ensure that satellites enter their orbits in the most energy efficient ways possible. This ensures that the amount of fuel required is kept to a minimum; an important factor on its own because the fuel itself has to be transported until it is used. If too much fuel has to be used then this increases the size of the launch rocket and in turn this greatly increases the costs.
Traditionally, there are the two main methods of placing satellites into orbit, using Shuttle and launch vehicle.
Many satellites are placed into geostationary orbit, and one common method of achieving this is based on the Hohmann transfer principle. This is the method use when the Shuttle launches satellites into orbit. Using this system the satellite is placed into a low earth orbit with an altitude of around 180 miles. Once in the correct position in this orbit rockets are fired to put the satellite into an elliptical orbit with the perigee at the low earth orbit and the apogee at the geostationary orbit as shown. When the satellite reaches the final altitude the rocket or booster is again fired to retain it in the geostationary orbit with the correct velocity.
Alternatively when launch vehicles like Ariane are used the satellite is launched directly into the elliptical transfer orbit. Again when the satellite is at the required altitude the rockets are fired to transfer it into the required orbit with the correct velocity. Naturally it would be possible to place a satellite directly into geostationary orbit, but this would take more energy and would not be feasible.
Launching Nano and Microsatellites
Global interest in nano and microsatellites (< 100kg) is increasing. The miniaturization of electronics, together with reliability and performance increase as well as reduction of cost, have allowed the use of commercials-off-the-shelf in the space industry, fostering the Smallsat use. Many nanosatellites (<10 kg) are used for educational purposes, and within the past few years nanosatellite applications have expanded to on-orbit technology demonstration/experimentation, telecommunications, and earth observation. These are the fastest growing segments in the satellite industry. ‘CubeSat’ is one of the most popular types of miniaturized satellites.
Nanosatellites and microsatellites find application in scientific research, communication, navigation and mapping, power, reconnaissance, and others including Earth observation, biological experiments, and remote sensing. There is also growing utilization of miniaturized satellites for military and defense applications. This environment generates demand for small satellite launches, as evidenced by the last ten years of launch activity.
As the cost of small satellite development is driven down through use of COTS components, standardised commercially available bus designs, and simplified manufacturing processes, the impact of launch cost becomes increasingly significant compared to the total mission budget. The space transportation industry is in need of low-cost, reliable, on-demand, routine space access. Both government and private entities are pursuing various small launch systems and architectures aimed at addressing this market need. A number of strategies have been proposed which enable multiple small satellites comprising a constellation to be launched together and efficiently separated on-orbit, thus reducing the total cost of launch.
Historically the small satellites have been launched through Rideshare missions, which is a type of multiple-manifested launch where a number of similarly sized payloads share a single vehicle launched to a mutually agreeable orbit. Ukrainian Dnepr-1 and Indian PSLV have been the most popular launch vehicles for satellites less than 50 kg. The popularity of these vehicles is most likely due to their early acceptance of small piggyback payloads and their relatively inexpensive price. From 2000 to 2009 the Dneper-1 rocket launched 40% of satellites with masses between 1 and 50 kg. The PSLV and the Space Shuttle were the only other launch systems to carry a double digit number of satellite.
Operators of tiny satellites don’t have many options to get to space, and typically have to hitch rides on launches of much bigger probes. That’s not always ideal, since it means waiting for someone else’s launch and possibly going to a less-than-desirable orbit. But with a launcher like the Electron, small satellite operators can potentially pay for an entire rocket ride for their hardware, and Rocket Lab says individual flights may start as low as $4.9 million.
For military applications responsive launch is a high priority goal (nominal 6-day call-up for ORS mission requirements)), the design compromises for a highly responsive launcher can adversely affect the cost and performance of the vehicle. Some of the launch vehicles are derived from decommissioned ICBMs, however they are restricted to government-sponsored use, or have issues relating to their life-span, requiring costly maintenance procedures.
However, launching satellites affordably as secondary payloads makes it difficult for the small satellite mission to launch when needed into the desired orbit, and with acceptable risk. Many countries are now developing dedicated launch options for microsatellites and nanosatellites. The clear advantage of a dedicated launch however, is that the destination orbit of the payload can be selected to best fit the mission and the date of launch can be chosen to coincide with the payload development and mission operation schedule.
A number of new launch vehicles aiming to address the microsatellite and nanosatellite launch capability gap are currently in varying stages of development. The payload capability of these vehicles ranges from 12 to 300 kg with specific launch costs in the range of current secondary payload opportunities. Notable examples include the Virgin Galactic LauncherOne which will be air-launched from the WhiteKnightTwo carrier aircraft and will have a capacity on the order of 225 kg to LEO, a 10 kg payload launcher deployed from the XCOR Aerospace Lynx Mk.III suborbital vehicle, and the DARPA ALASA program involving several companies working towards the launch of a 45 kg payload to orbit for less than $1M. These vehicles will support the dedicated launch of microsatellites and nanosatellites, avoiding the potentially mission critical issues related to secondary payload launch opportunities.
NASA’s Affordable Vehicle Avionics (AVA) technology offers access to space for small-payload SLV operators with an ability to provide dedicated launch to Low Earth Orbit (LEO), when and where they need. Rocket Lab, the New Zealand-based, Silicon Valley-funded space launch company, is looking for a new launch site for its Electron rocket—and it is targeting the United States. Rocket Lab has already successfully launched two test flights of its battery-powered, partly 3D-printed Electron rockets, one in May 2017 and another in January 2018. Electron is designed for a nominal payload of 150 kg to a 500 km sun-synchronous orbit. Rocket Lab is able to tailor the vehicle to specific mission requirements including a range of sun-synchronous altitudes in circular or elliptical orbits at inclinations between 39 and 98 degrees.
ISRO’s big scheme to send small rockets into space
On 18 June 2016, ISRO launched twenty satellites in a single vehicle, and on 15 February 2017, ISRO launched one hundred and four satellites in a single rocket (PSLV-C37), a world record. India has used its Small-LV, the Polar Satellite Launch Vehicle (PSLV), to put 42 Smallsats into orbit. From those, only 9 Smallsats were Indian, the rest were manufactured by 15 different countries. Since PSLV has a payload capacity of about 1,750 kg, the majority of the Smallsats were launched as secondary payloads.
India’s space agency aims to create a consortium of companies to build and market a small rocket to launch low-weight satellites at lesser cost and within shorter durations, as it seeks to tap into burgeoning global demand for such services. Led by Antrix Corp — the commercial arm of the Indian Space Research Organisation — the consortium will include engineering major Larsen & Toubro, Godrej Aerospace and Hindustan Aeronautics Ltd. The combine will help Isro build a small rocket capable of carrying 500 kilogram satellites into the lower earth orbit. “Antrix is working on a model to involve industry from the beginning.
Our aim is that one or two rockets will be launched by Isro, the industry should then make the rockets and launch satellites,” said K Sivan, chairman of Isro in an interview with ET. He said Isro has approached these companies and that “they are all interested”. “The price of a satellite launch on this small rocket is expected to be less than one-fifth of the current launch costs,” Sivan added. The first development flight or launch of the rocket will be by 2019. By involving companies such as L&T, Godrej and HAL, in the initial stages the space agency expects to improve the manufacturing process and bring down the cost of the rocket.
Typically, Isro takes around 45 days to assemble its workhorse the Polar Satellite Launch Vehicle (PSLV). The smaller rocket, to be powered by a solid booster, is expected to be ready for launch in three days. It is being designed to place low-weight satellites in the low earth orbit of around 500 kilometres. “We are looking at some disruptive technologies with this (rocket),” said Sivan.
SpaceX launches a record 143 satellites on one rocket
In Jan 2021, SpaceX successfully launched an ambitious rideshare mission as one of its veteran boosters hoisted 143 small satellites — a new record for a single rocket — into space before nailing a landing at sea. SpaceX launched a Falcon 9 rocket Sunday from Cape Canaveral with 143 small satellites, a record number of spacecraft on a single mission, giving a boost to startup space companies and stressing the U.S. military’s tracking network charged with sorting out the locations of all objects in orbit.
The Falcon 9’s reusable first stage booster — flying for the fifth time — landed on SpaceX’s “Of Course I Still Love You” drone ship in the Atlantic Ocean southeast of Miami nearly 10 minutes after liftoff. SpaceX said it also retrieved the rocket’s payload fairing halves after they parachuted back to Earth in the Atlantic. The rocket’s second stage powered into orbit with its 143 satellite passengers, flew over Antarctica, then briefly reignited its engine while heading north over the Indian Ocean.
The launch Sunday carried payloads for Planet, Swarm Technologies, Kepler Communications, Spire, Capella Space, ICEYE, NASA, and a host of other customers from 11 countries. The payloads ranged in size from CubeSats to microsatellites weighing several hundred pounds. The Falcon 9 rocket will also delivered 10 more of SpaceX’s Starlink internet satellites into space, the first Starlink craft to head for a polar orbit.
SpaceX aimed to placed the satellites into an orbit roughly 326 miles (525 kilometers) in altitude, with an inclination of 97.5 degrees to the equator. The company confirmed an on-target orbital injection after the second burn of the Falcon 9’s upper stage engine, setting the stage for a carefully-choreographed payload deployment sequence that took more than a half-hour to complete. The mission Sunday broke the record number of satellites on a single launch, exceeding the 104 spacecraft launched on an Indian Polar Satellite Launch Vehicle in 2017.
But it could take some time to sort identify each of the 143 satellites, along with debris generated from the Transporter-1 launch. The Space Force is responsible for maintaining the catalog of artificial space objects, and screening for potential collisions between satellites and space debris, which could generate even more junk in orbit. “Releasing so many objects on the same launch presents a huge challenge for the people that are tasked to track and identify those objects,” said Brian Weeden, director of program planning and technical advisor for the Secure World Foundation. “It’s really difficult for them to do that unless they have a lot of advance knowledge about how many payloads there are, when are they going to be deployed, what orbit are they deployed in, how are they going to be deployed? There are a lot of little nuances there that can help, but they have to know that information.”
SpaceX’s prices undercut those of small satellite launch companies like Rocket Lab and Virgin Orbit. Those launch providers offer rides for payloads into different types of orbits, where the small satellite owner has the choice of altitude and inclination. The Transporter missions from SpaceX are more akin to a train or bus line than a taxi or an Uber, says Peter Beck, Rocket Lab’s founder and CEO. They are cheaper, but don’t always get you exactly where you need to go. Sun-synchronous orbit, in which satellites fly in a north-south direction around Earth, is a popular destination for Earth observation satellites because it offers regular revisits over imaging targets at the same time of day, allowing the collection of imagery under the same lighting conditions.
SpaceX launched a rideshare mission to sun-synchronous orbit in December 2018 with 64 small satellites on-board. But that mission, named SSO-A, was managed by Spaceflight, which purchased the full capacity of a Falcon 9 rocket from SpaceX. Spaceflight returned to SpaceX as a customer on the Transporter-1 mission, opting to buy a fraction of the Falcon 9’s overall capacity rather than booking the entire rocket.
Rocket Lab wins NRO contracts for back-to-back launches
Rocket Lab announced June 2020 that it received the NRO contracts for a pair of Electron missions from the company’s Launch Complex 1 in New Zealand in the late spring of 2021. The launches will take place from the existing launch pad there, known as LC-1A, as well as a second pad, LC-1B, scheduled to be completed by the end of the year.
“We’re looking forward to having two vehicles sitting on two pads simultaneously, and we’ll see how close together we can actually get them to launch,” he said. “We’re planning internally to see how close we can get those two together.” Conducting the back-to-back launches is intended to demonstrate the ability to swiftly launch national security payloads. “It’s going to be a significant milestone for us and the NRO to demonstrate true responsive space in action,” he said. “When it comes to national security, there shouldn’t be any waiting room to get into orbit.”
The NRO used its Rapid Acquisition of a Small Rocket (RASR) contract vehicle for the two launches, which it also used to launch three payloads June 13 on the most recent Electron rocket. NRO also launched a payload on the previous Electron launch in January. While NRO has been a major customer of late for Rocket Lab, Beck said the company has good relationships with commercial customers and other U.S. government agencies, including DARPA, NASA and the U.S. Air Force.
The NRO, which develops the nation’s spy satellites, supports both the intelligence community and the Defense Department. One of the priorities is to figure out new ways to collaborate with the U.S. Space Force and U.S. Space Command, said Parker. “That’s going to be a big push for us going forward. Commercially developed small satellites are one area of particular interest, said Parker. The NRO is looking at using small satellites to take advantage of the growing availability of smaller launch vehicles that can provide a faster response.
Rocket Lab is still planning to attempt to recover an Electron first stage on the rocket’s 17th launch, which Beck said will likely be in October or November. (The next launch will be the 13th flight of the rocket.) That is part of an effort the company announced last year to recover and reuse those first stages to allow it to increase its launch rate without major upgrades to its manufacturing capacity.
China launches satellite on low-cost solid-fuel rocket
China launched its Centispace-1-s1 satellite on a Kuaizhou-1A low-cost solid-fuel carrier rocket. It was launched from Jiuquan Satellite Launch Centre in northwest China. This is the second commercial launch by the Kuaizhou-1A rocket, a low-cost solid-fuel carrier rocket with high reliability and a short preparation period, designed to launch low-orbit satellites weighing under 300 kgs, state-run Xinhua news agency reported.
The first launch in January, 2017 sent three satellites into space. The Kuaizhou-1A was developed by a rocket technology company under the China Aerospace Science and Industry Corporation (CASIC). The Centispace-1-s1 was developed by Innovation Academy for Microsatellites of the Chinese Academy of Sciences. It is a technology experiment satellite for the low-orbit navigation enhancement system being developed by Beijing Future Navigation Technology Co, the report said.
Japan launches micro satellite rocket
The Japan Aerospace Exploration Agency (JAXA) launched in Feb 2018 the world’s smallest rocket with the ability to put a micro-satellite into orbit, following a failed attempt and several postponements over the last year. JAXA had launched the first of these rockets on January 2017, which fell into the sea after launch due to short-circuit caused by vibrations during take-off.
The launch of the low-cost rocket — with a height of 10 metres and 53 centimetres in diameter — took place from the Uchinoura Space Centre in Kagoshima prefecture and was aired live on YouTube, Efe news reported. The rocket, an improved version of JAXA’s SS—520, was carrying a micro-satellite weighing three kilograms and was developed by the University of Tokyo to capture images of the Earth’s surface.
JAXA had launched the first of these rockets on January 2017, which fell into the sea after launch due to short-circuit caused by vibrations during take-off. The current launch aimed to test the ability of the Japanese aerospace agency to launch low-cost rockets that can put micro satellites into space at affordable rates against a background of growing demand from the private sector. Satellites for weather observation or defence that are in use are normally large and are commissioned by the authorities. In recent years there has been increase in the development of smaller ones by private firms for use in traffic control or geographical studies.
Virgin Orbit Launches Rocket off a 747 Aircraft, Puts Nine Satellites in Space
During the test flight, LauncherOne was dropped mid-air from the underside of a modified Boeing 747 nicknamed Cosmic Girl some 35,000 feet over the Pacific at 11:39 am PT (19:39 GMT), before lighting its NewtonThree engine to boost itself out of Earth’s atmosphere, demonstrating its first successful journey into space.
The rocket, a 70-foot launcher tailored for carrying small satellites to space, aimed to place the 10 tiny satellites into orbit for NASA roughly two hours into the mission, though Virgin Orbit had not confirmed whether they were deployed as planned. After the satellites were deployed, the rocket performed a deorbit burn to safely and destructively reenter Earth’s atmosphere.
The rocket flew a group of tiny satellites on behalf of NASA’s Educational Launch of Nanosatellites, or ELaNa, program, which allows high school and college students to design and assemble small satellites that NASA then pays to launch into space. The nine small satellites that Virgin Orbit flew on Sunday included temperature-monitoring satellite from the University of Colorado at Boulder, a satellite that will study how tiny particles collide in space from the University of Central Florida, and an experimental radiation-detection satellite from the University of Louisiana at Lafayette.
Virgin Orbit spun off from Virgin Galactic, a company focused on suborbital human spaceflight, in 2017. Virgin Orbit conducted several “drop tests” of its LauncherOne rocket, which involved flying the vehicle out over the Pacific and letting it plunge into the ocean to vet the 747’s release mechanism. Previous launches were aborted in May 2020 due to engine trouble, and in December due to a surge in coronavirus cases. Virgin Orbit’s first attempt to put a rocket in orbit came last May, when LauncherOne malfunctioned shortly after release and the flight was aborted. That failure wasn’t unexpected.
Using Balloons to Launch Satellites
Today, most air-launch-systems that are being pursued involve aircraft bringing rockets or spacecraft with rocket motors to launch altitudes – such as Virgin Galactic’s SpaceShipTwo, Virgin Orbit’s LauncherOne, or the Stratolaunch air carrier. With the goal of leveraging new technologies and lowering the costs of launching payloads into space, some truly innovative and novel ideas are being put forth. This includes the idea of using balloons to carry rockets to very high-altitudes, then firing the payloads to their desired orbits.
Los Angeles-based LEO Aerospace company chose to investigate the equally valid method of relying on a lighter-than-air (LTA) platform to get payloads to space. Also known as “Rockoons”, this concept has informed Leo Aerospace‘s fully-autonomous and fully-reusable launch system – which consists of a high-altitude aerostat (balloon) and a rocket launch platform. With the first commercial launches slated for next year, the company plans to use this system to provide regular launch services to the microsatellite (aka. CubeSat) market in the coming years.
Unlike conventional rockets, which rely on massive amounts of propellant to achieve escape velocity and send payloads to orbit, air-launch-systems rely on the comparatively cost-effective method of transporting a payload to high altitude where it can then be sent to Low Earth Orbit (LEO). This reduces the amount of propellant needed but also involves launching a rocket from altitudes where air resistance is lower and less force is needed to escape Earth’s gravity. All of this allows for much smaller and lighter launch vehicles to be used, which leads to significantly reduced costs. This method is especially effective when it comes to small payloads like microsatellites, which are becoming all the more common.
The central components of this launch system are the Regulus Orbital launch platform and the Orbital Rocket. The Regulus platform provides autonomous flight control through a series of burners (which ensure that the aerostat remains buoyant) and a rotational control system of bipropellant thrusters, all of which are mounted to an insulated body composed of composite material.
Meanwhile, the Orbital Rocket is a miniature two-stage launch vehicle that is attached to the platform via an actuator and a launch rail. Once the aerostat reaches a deployment altitude of 18,000 meters (60,000 ft), the rocket will launch and carry the payload to its desired orbit. According to the company’s mission profiles page, the system will be capable of conducting multiple types of deliveries to different altitudes.
Because of this, the rocket, aerostat, and machinery needed for inflating it can all be placed into a standard shipping container, loaded onto a semi-truck, and then shipped wherever it is needed. The trailer cab also serves as the initial communications station for the launch. This level of mobility and flexibility is one of the characteristics that could make aerostat platforms effective at delivering emergency aid and relief services. As Rudy said: “We are beginning to uncover many different use cases for the reusable and autonomous aerostat platform that we are developing. It is entirely mobile and fits into a standard shipping container, making it easy to transport and store. Additionally, it is simple to operate and incredibly robust. Unlike lifting gas balloons, our system can still operate with a hole the size of a car in the balloon material. Our collaborators are excited to leverage these capabilities to rapidly deploy sensor suites in disaster areas post-hurricane or provide emergency relief supplies in places that are difficult to reach. It has been incredible to work with groups like the Army Space and High-Altitude Experiments branch to identify and solve such a range of problem cases.
“The development and production cost of a balloon system is orders of magnitude less than using an airplane,” said Rudy. “Compared to other balloon systems that use lifting gas, our hot-air architecture is fully and rapidly reusable. We can conduct dozens of launches with a single system before refurbishments are required.”
These will range from suborbital missions – where payloads are sent to an altitude of 18 km (60,000 ft) – to orbital missions, where CubeSats will be sent to sun-synchronous orbit (SSO) of 550 km (340 mi). Another possibility they are sure to mention involves the delivery of humanitarian aid or emergency communications equipment to remote regions that are inaccessible to fixed-wing aircraft, drones, or other aerial vehicles. The company also plans to incorporate gliders and drones that can deploy from their aerostats, thus offering other mission profiles – such as drone monitoring, scientific experiments, and communications services. In addition to being a more cost-effective means of placing small payloads in orbit, the launch system also has the benefit of being very compact.
NASA SBIR on Nano/Micro Satellite Launch Vehicle (NMSLV)
The Nano/Micro Satellite Launch Vehicle (NMSLV) will provide the nation with a new, small payload access to space capability. The primary objective is to develop a capability to place nano and micro satellites weighing up to approximately 20 kilograms into a reference orbit defined as circular, 400 to 450 kilometer altitude, from various inclinations ranging from 0 to 98 °.
Proposals should include, but not be limited to, the following areas:
Orbital booster designs of system/architectures capable of reducing the mission costs associated with the launching of small payloads to LEO. The designs should focus on the following:
- Develop and implement technologies for small, lightweight, robust avionics packages for launch vehicle control, systems monitoring, autonomous flight termination, separation systems and TDRS transmitter to support the launch test.
- Requirements (acceptable to range safety organizations) for Autonomous Flight Termination System(s) for Nano/Micro Launchers.
- Develop and test the propulsion system for the NMLV by production reducing cost.
- Development of a ground operations concept to show how the launch vehicle will be integrated, processed and launched.
Performance predictions, cost objectives, and development and demonstration plans for the NMSLV.
All proposed sub-orbital booster technologies should be traceable to an orbit-capable Small Launch Vehicle (SLV), whereby specific technologies are identified for Phase II development and test
James Russell, principal investigator for NASA’s AIM atmospheric research satellite at Hampton University, said launches of large clusters of satellites can put other spacecraft at risk. Russell said the AIM satellite flies at roughly the same altitude as the Transporter-1 mission’s target orbit. “It’s an uncalculated collision risk,” Russell told Spaceflight Now “They have not calculated what the collision probability is once they launch the smaller satellites.”
Many of the satellites on the Transporter-1 mission have no way to change their orbit. AIM also carries no propulsion system, so there would be no way to steer clear of a collision, according to Russell. Russell called for the U.S. government to “create policy” and for Congress to “make laws” setting safety requirements to limit the chances of in-space collisions. “That doesn’t exist right now,” Russell said. “I think the process for getting this in place is moving, but it’s moving at a snail’s pace.”The Federal Communications Commission decided last year not to immediately introduce any new major requirements for commercial satellite operators. The FCC discussed requiring commercial satellites above a certain altitude — where they might remain in orbit for decades — to have propulsion to maneuver and deorbit at the end of their missions.
Launching Microsatellite Constellations
The rise in launch and use of small satellites in the past decade, a result of improved functionality through technology miniaturisation and alternative design philosophies, has spawned interest in the development of distributed systems or constellations of small satellites. The use of small satellites in constellations has also been successfully demonstrated by a number of microsatellite-class missions, including the Disaster Monitoring Constellation (DMC) and RapidEye Earth observation missions and the ORBCOMM satellite communications system.
However, the current launch paradigm of secondary payload manifesting of small satellites limits the ability of these constellations to be successfully deployed into orbit. In particular, the lack of control on launch schedule and destination orbit prohibits the use of multiple secondary launch opportunities by constellations which require accurately coordinated orbits and multi-plane configurations. This issue is further compounded by technology, mass, and volume constraints on propulsion system capability to maintain low development and manufacturing costs and comply with launch vehicle regulations. These constraints can be particularly restrictive for the smaller nanosatellite and picosatellite class platforms which are therefore typically limited in their ability to individually manoeuvre into their mission orbits
In order to enable the cost-effective realisation of small satellite constellations a number of deployment strategies have been proposed which allow the launch of a complete multi-plane constellation on a single vehicle with satellite distribution occurring on-orbit.
The successful demonstration of co-operative small satellite systems will also generate interest in the development of commercial constellations, swarms and clusters, establishing a definite market for a small satellite launch capability