ViviSat, a joint venture between aerospace companies ATK [ATK] and U.S. Space LLC, is offering governments and private industry a free-flying satellite “jetpack” to extend the service life of commercial and national security satellites systems that have run out of station-keeping propellant.
This free-flying satellite, called a Mission Extension Vehicle (MEV), works with satellites that hover in geostationary orbit, or 36,000 km above the earth’s average sea level and following the direction of the earth’s orbit. Once it reaches geostationary orbit, the MEV will rendezvous with the customer satellite and extend a probe-like device through the nozzle throat of the satellite’s apogee kick motor. Once the smallest part of the probe is through the satellite’s nozzle throat, the MEV expands the probe and pulls the customer satellite towards it and latches on, like a jetpack, to provide a rigid connection between the two.
The MEV can stay connected to the satellite for as long as 16 years, providing propulsion and altitude control. But Tom Wilson, vice president and general manager of ATK’s space systems division and a member of ViviSat’s board of directors, believes most customers would choose much less than that.
“(It’s) good for 16 years and a client may elect to do all, or a portion, of that 16 years,” Wilson told Defense Daily yesterday during a phone interview. “We’re thinking most clients would want from two-to-four years of life extension for their satellite, so we can anticipate servicing a number of clients with one Mission Extension Vehicle.”
Flexibility is what makes the MEV such an excellent opportunity for extending the life of satellites, ViviSat CEO Craig Weston told Defense Daily yesterday in a phone interview. He said if a satellite propulsion system was broken or leaked fuel, since you wouldn’t be able to fix the propulsion system itself or refuel the vehicle, you could just attach the MEV. In addition, Weston said the MEV uses already-proven heritage technology, which makes it a very capable system.
“The most challenging thing is the rendezvous, proximity operations and the docking,” Weston said. “ATK has made a significant investment (in a zero gravity rendezvous and proximity operations laboratory) to demonstrate the most challenging portion of the mission, so we’re pretty confident the whole design is going to work.”
Weston also said the Defense Department, in addition to private industry, is a prime candidate for the MEV for two reasons: Cost savings in extending the life of its satellites and the ability to host payloads on the MEV, which the government is increasingly pursuing as defense budgets tighten.
“If you think about some of the very sophisticated (satellites) DoD builds, they cost an awful lot of money and take a long time (to build),” Weston said. “So to be able to extend the life of an Advanced Extremely High Frequency (AEHF) or a Space-Based Infrared System (SBIRS) satellite for two to four years would be a tremendous cost avoidance to the government in terms of delaying building follow-on satellites and we think it would be very cost efficient.
“(The) second consideration is that we do have the ability to host secondary payloads on the MEV, so we can see the government might be interested in putting some secondary payloads on the MEV as it performs its primary mission of life extension,” Weston said.
In addition to AEHF and SBIRS satellites, Weston said the MEV is compatible with “80-percent” of both commercial and national security satellites–those with the apogee kick motor. Wilson said other government satellites the MEV is compatible with include the Tracking and Data Relay Satellite System (TDRSS) and the Geostationary Operational Environment Satellites (GOES).
But Wilson said the MEV would not be compatible with satellites with a xenon ion propulsion system (XIPS), such as Boeing’s [BA] Wideband Global SATCOM (WGS) system. Wilson said the company “absolutely will” make the MEV compatible with WGS eventually, but for right now, ViviSat is focusing on the other 80 percent of the market.
Wilson said it would nominally take 10 months for the MEV to go from launch to connection with its first customer satellite in geosynchronous orbit since the MEV uses a low thrust electric propulsion system to reach its working orbit.
Weston also said ViviSat has not signed a contract with a customer yet, but the company has talked to all the major and second-tier commercial operators and is in negotiations with several of them. Weston also said ViviSat has also talked to a number of foreign-based satellite operators, in addition to the U.S. government.
Weston said ViviSat was originally founded in October 2010 to provide general satellite servicing such as on-orbit assembly, integration and other robotic autonomous missions in orbit, but the near-term focus of ViviSat is on the “jetpack” life extension capability.