In October 2010 National Aeronautics and Space Administration (NASA), published a report about the benefits and feasibility of servicing satellites on-orbit, the On-Orbit satellite servicing study. This project report explains that most satellites can serve well beyond their useful life, but after fuel reserves are depleted a satellite cannot make orbit corrections and must be decommissioned. There is also the problem that older satellites sport older technology without the ability for an upgrade. If there was a customer collaboration, an agency paradigm shift, a robotic improvement, and cost effective launch vehicle then the report shows satellite servicing is a viable option. Great news! All the assumed requirements seem to be falling in place.
The Defense Advanced Projects Research Agency (DARPA) in collaboration with NASA have decided to work together designing new satellites with serviceability in mind (Mizokami, 2017). There are plans to refuel Landsat 7 with the help of an unmanned system design to service satellites. There are two main companies Space Systems Loral (SSL) and Orbital ATK developing the technology for on-orbit satellite refueling, and repair. The scientific rivalry turned into judiciary game when SSL sued Orbital over trade secrets theft, and Orbital sue DARPA for giving the bid for the ob-orbit service contract development to SSL (Orlotti, 2017). Orbital lost the suit and DARPA has selected SSL to develop the unmanned system that will service satellites using a robotic arm and very difficult rendezvous maneuvers. The unmanned system will need a low cost launch platform to make serviceability an economical sound option.
Commercial space exploration companies like Orbital ATK, Sierra Nevada, Boeing and SpaceX have demonstrated lower launch cost mission to space as explained by Edgar Zapata in a NASA report An assessment of cost improvements in the NASA COTS/CRS program and implications for future NASA missions. If the service unmanned system could orbit Earth and get its fuel and supplies from a resupply mission to the International Space Station (ISS), there is the possibility that mission cost could be even lower. NASA has just finished a series of test for it Robotic Refuel Mission 3 (RRM3) that will launch aboard SpaceX resupply mission to the ISS in late 2018 (Lloyd, 2018). RRM3 will test the technology to refuel satellites from the ISS (Lloyd, 2018). Servicing satellites from the ISS missions is not new. There are case studies demonstrating how the Space Shuttle program and astronauts were able to repair multiple satellites and most notably the Hubble telescope.
The service still depend on costumers willing to have their satellites serviced. NASA will test the technology of Restore-L, the DARPA-NASA collaboration to service satellites, and the RRM3 on a NASA satellite first. Once the technology is proven is expected that telecommunication, and Earth sensing commercial satellites will find it beneficial to service their satellites. Hopefully the NASA missions will show that a mission to refuel a satellite is cost effective and achievable.
9/5/2018 Update
I wanted to address the main question regarding on-orbit satellite servicing; Why do it?
Currently developing the technology to refuel a satellite on-orbit has not made sense because of the high cost of launching a space mission. With cost coming down thanks to new technology and competition from commercial companies compare to the space shuttle as presented in Zapata's report, it makes financial sense to extend the life of satellites instead of creating a new one. The new trend for satellites is smaller cheaper satellites, think Cubesat. These satellites are cheaper to make and launch thanks to the smaller dimension and weight they can hitch a ride on a space mission. These smaller cheaper satellites are loaded with newer technology and sensors that serve well for remote sensing (Vanian, 2018). While some sensors can be made smaller, there are physical limitations to other payload, for example antennas, and telescopes. An antenna functionality is driven by its size, and a telescope needs to capture light to magnify it.
Telecommunications companies are seeing less return on investments from certain bandwidth, so updating their equipment in space may not translate into direct revenue (Russell, 2018). An other satellite operators are wary to spend capital on technology that might be obsoleted in incoming years in a uncertain industry (Erwin, 2018). More companies, and agencies like NASA are starting to realize the benefits of extending satellite life while also developing the technology to remove debris from valuable orbits. There could be a time where there is no where to put any more satellites on orbit, and having the ability to remove or extend the life of an asset already occupying that orbit will be valuable. From an economic stand point of view developing an expensive satellite and paying for an expensive launch could be risky if the available technology drastically changes in couple of years and launch prices drop.
9/12/2018 Update
Kepler the $600 million dollar planet hunter telescope is put in sleep mode because a thruster is malfunctioning and the telescope is running out of fuel (Hawkes, 2018). It is uncertain how many more missions the spacecraft can operate, and this might be the end of a very successful campaign to identify planets in the Goldie locks zone. This high profile and expensive space asset could benefit from a system able to service the thruster and refuel to prolong the life of the program. For prolonged space presence of scientific assets there must be a way to cope with failures. The Hubble telescope is a great example of salvaging a mission that otherwise would have been a failure. Space systems are highly engineered, but are not immune to failure.
9/27/2018 Update
The American Institute of Aeronautics and Astronautics held a panel discussion on this years Space Forum, at Orlando, Florida where experts discussed the future of on-orbit satellite servicing. There are no current service providers, but service is estimated to be a $700 million industry by 2026 (McDonald, 2018). The main focus will be for the new industry will be refueling telecommunications satellites avoiding sending the satellites to a a graveyard orbit after they run out of fuel (McDonald, 2018). The first demonstration of the technology will be performed by NASA in cooperation with DARPA to refuel the LandSat 7 satellite by 2020 (Thoreson, 2016). DARPA has already demonstrated chasing and docking technology when in 2007 a pair of satellites met and dock from 400 kilometers in the Orbital Express mission (Canaday, 2018).
Orbital ATK has a contract with Intelsat to attached an auxiliary propulsion vehicle, Mission Extension Vehicle, to Intelesat-901 in 2019 in order to extend the life of the satellite for five more years (Canaday, 2019). This vehicle uses an ion thruster to keep the client vehicle in the correct orbit, and interfaces with using the adapter ring that the original satellite used to attach to the launch vehicle (Canaday, 2018).
The systems being developed that will service satellite sin the future:
Restore-L: NASA Goddard Space Flight Center with DARPA (Sullivan, 2018).
MEV: Mission Extension Vehicle from Northrop Grumman subsidiary Orbital ATK , the vehicle will rendezvous with the client attach itself to it and provide continued propulsion (Sullivan, 2018).
ESS Space Drone: Effective Space Solution Drone vehicle will launch 2020 to provide satellite relocation, and propulsion to clients (Sullivan 2018).
Airbus e-Deorbit: is a vehicle intended to capture debris in LEO orbits to bring it back to Earth.
RSGS: Robotic Servicing of Geosynchronous Satellites (RSGS) is a collaboration between DARPA and Space Systems Loreal (SSL) to create a refueling system that includes a robotic arm for repairs and upgrades of client satellites (Sullivan , 2018).
There is also interest in Payload Orbital Delivery (POD), the POD flies to a satellite and attaches itself to deliver a new instrument, or provide propulsion. These PODs are low mass so they could hitch rides and fill the capacity of other space mission. An on-orbit Attachable Capabilities (OAC) is a system that attaches to the satellite physically and interfaces with PODs, and the power, and data from the host satellite. The OAC give another option to upgrade the capabilities of a satellite on-orbit.
The future of space systems will depend in dealing with failures, and being able to prolong, upgrade, and extend the useful life of space systems. Servicing on-orbit has to become a reality in order to advance space exploration. Commercial launch companies have shown reusability brings the cost down for space systems. It follows that space systems should follow this path of sustainability.
References
Black, C. (2017, February 12). Look Ma! No Canadarms!!! MDA & Orbital ATK battle for US on-orbit satellite serving contracts. The Commercial Space Blog. Retrieved from http://acuriousguy.blogspot.com/search?q=satellite+repair
Canaday, H. (2018, June). Servicing revolution. Aerospace America. Retrieved from https://aerospaceamerica.aiaa.org/features/servicing-revolution/
Erwin, S. (2018, June 10). In-orbit services poised to become big business. Space News. retrieved from https://spacenews.com/in-orbit-services-poised-to-become-big-business/
Hawkes, A. (2018, March 14). NASA's Kepler spacecarft nearing the end as fuel runs low. National Aeronautics and Space Administration. Ames Research Center, California's Sillicon Valley. Retrieved from https://www.nasa.gov/feature/ames/nasa-s-kepler-spacecraft-nearing-the-end-as-fuel-runs-low
Klotz, I. (2017, July 14). Orbital loses bid to stop DARPA satellite-servicing project. Space.com. Retrieved from https://www.space.com/37493-orbital-suit-dismissed-darpa-satellite-project.html
Lloyd, V. (2018, June 20). Robotic refueling mission 3 completes crucial series of tests. National Aeronautics and Space Administration. Retrieved from https://www.nasa.gov/feature/goddard/2018/robotic-refueling-mission-3-completes-crucial-series-of-tests
McDonald, M. (2018, September 17). On-orbit servicing could be a huge industry. Panel Discussion at Space Forum September 17, 2018. American Institute of Aeronautics and Astronautics Space Forum. Retrieved from https://livestream.com/accounts/6056055/events/8367524/videos/180445220
Mizokami, K. (2017, December 27). DARPA and NASA team up to design refueling satellites. Popular Mechanics. Retrieved from https://www.popularmechanics.com/military/a14506288/darpa-and-nasa-team-up-to-design-refueling-satellites/
National Aeronautics and Space Administration (2017, August 3). Frequently asked questions form the public. Retrieved from https://www.nasa.gov/kepler/faq#d
Mizokami, K. (2017, December 27). DARPA and NASA team up to design refueling satellites. Popular Mechanics. Retrieved from https://www.popularmechanics.com/military/a14506288/darpa-and-nasa-team-up-to-design-refueling-satellites/
National Aeronautics and Space Administration (2017, August 3). Frequently asked questions form the public. Retrieved from https://www.nasa.gov/kepler/faq#d
Orlotti, B. (2017, March 28). Cloak and dagger between Space Systems Loral and Orbital ATK. The Commercial Space Blog. Retrieved from http://acuriousguy.blogspot.com/search?q=satellite+repair
Russell, K. (2018, February 13). Why the market is ready for on-orbit satellite servicing. Via Satellite. Retrieved from https://www.satellitetoday.com/innovation/2018/02/13/market-ready-orbit-satellite-servicing/
Sullivan, B. R., Parrish, J. C., Roesler, G. (2018). Upgrading in-service spacecraft with on-orbit attachable capabilities. American Institute of Aeronautics and Astronautics SPACE Forum. 17-19 September, 2018, Orlando Florida. doi-org.ezproxy.libproxy.db.erau.edu/10.2514/6.2018-5223
Thoreson, H. (2016, September 16). On-Orbit servicing will lower cost and increase satellite life spans. Space. American Institute of Aeronautics and Astronautics. Retrieved from https://space.aiaa.org/On-OrbitServicing/
Vanian, J. (2018, July 18). Why smaller satellites and cheaper tech are fueling the space boom. Fortune. Retrieved from http://fortune.com/2018/07/18/space-satellites-brainstorm-tech/
Russell, K. (2018, February 13). Why the market is ready for on-orbit satellite servicing. Via Satellite. Retrieved from https://www.satellitetoday.com/innovation/2018/02/13/market-ready-orbit-satellite-servicing/
Sullivan, B. R., Parrish, J. C., Roesler, G. (2018). Upgrading in-service spacecraft with on-orbit attachable capabilities. American Institute of Aeronautics and Astronautics SPACE Forum. 17-19 September, 2018, Orlando Florida. doi-org.ezproxy.libproxy.db.erau.edu/10.2514/6.2018-5223
Thoreson, H. (2016, September 16). On-Orbit servicing will lower cost and increase satellite life spans. Space. American Institute of Aeronautics and Astronautics. Retrieved from https://space.aiaa.org/On-OrbitServicing/
Vanian, J. (2018, July 18). Why smaller satellites and cheaper tech are fueling the space boom. Fortune. Retrieved from http://fortune.com/2018/07/18/space-satellites-brainstorm-tech/
