Planetary orbit insertion failures (part 1)

by Andrew J. LePage
Monday, June 16, 2014

One of the most crucial phases of many interplanetary missions is orbit insertion. Everything must go right the first time or the spacecraft fails to enter orbit around its target. And, all too often, there are no practical opportunities at a second chance, so an orbit insertion failure usually translates into a mission failure. At this moment, there are a half a dozen spacecraft en route to various targets throughout the solar system destined to enter orbit around their targets. It seems like this is a good opportunity to review orbit insertion failures over the last four decades of planetary exploration to see what can go wrong.

Artist concept of Akatsuki in orbit around Venus. (credit: Akihiro Ikeshita)

The commercial remote sensing boom

by Jeff Foust
Monday, June 16, 2014

A couple of years ago, the health of the commercial satellite remote sensing industry, at least in the United States, wasn’t good. Commercial interest in high-resolution images of the Earth from space wasn’t as high as the industry forecast back in the 1990s, when a new generation of companies—enabled by changes in national policy—developed satellites to serve this market. The US government had helped prop up the industry, but by 2012 the National Geospatial-Intelligence Agency (NGA) was cutting back on its purchases of commercial imagery, undermining the business cases for the two companies selling such imagery, DigitalGlobe and GeoEye (see “EnhancedView’s cloudy future”, The Space Revuew, May 7, 2012). Later that year, those two companies merged under the DigitalGlobe name.

Skybox Imaging’s first two satellites, SkySat-1 and -2, in the company’s clean room. SkySat-1 is in orbit with SkySat-2 slated for launch this year. Google announced plans last week to acquire Skybox for $500 million. (credit: Skybox Imaging, Inc.)

Today, though, the sector is remarkably vibrant. While DigitalGlobe continues its approach of selling high-resolution imagery to government and commercial customers, a number of smaller startups seek a different approach though the development of constellations of smaller satellites that provide imagery more frequently. One of those startups is now on track for a significant deal as others try and enter the market, but that vibrancy doesn’t necessarily translate into long-term viability.

Secret optics

by Dwayne A. Day
Monday, June 2, 2014

When it comes to spaceflight it is easy to get lost in the technology—engines, capsules, satellites, landers, and heat shields. Too often the people who build them are overlooked or forgotten and never get the credit or the opportunity to tell their stories.
This is even worse when it comes to classified space programs, where the people involved are not allowed to discuss their involvement as long as the program remains classified and sometimes even after it has been declassified.

Pressel’s goal was to not only explain what he and his fellow engineers at Perkin-Elmer Corporation did, but also to give credit to the often brilliant and always hard-working people who toiled away in secrecy on a major project at the same time that NASA was preparing to send astronauts to the Moon.

Fortunately, this isn’t always the case. In the fall of 2011, the National Reconnaissance Office (NRO) declassified two major Cold War reconnaissance satellite programs, the GAMBIT and HEXAGON. GAMBIT, which operated from 1963 until 1984, was a high-resolution camera system that peered down on the Soviet Union taking incredibly detailed photographs. HEXAGON, which involved 19 operational satellites launched between 1971 and 1985, was powerful in two ways: it also took highly detailed photographs and had the ability to see and map, in stereo, the whole landmass of the Earth, making it impossible for America's adversaries to hide anything from sight.
The NRO released a large number of documents about both programs, including lengthy official histories (although the release of documents has essentially stopped for the past year). But even that declassified material has huge holes in it, such as detailed discussion of how the subsystems were built, who built them, and how they overcame problems during design. As one example, we know that the GAMBIT-1 (KH-7) and the GAMBIT-3 (KH-8) systems actually flew, but the released documents provide very little information on the rejected GAMBIT-2 design. Nor do the official histories reveal much about the development of HEXAGON’s immensely complex camera system, or even the spacecraft propulsion and control system that supported it in orbit.