Base-led experiments to visit space station

  • Published
  • By Michael P. Kleiman
  • 377th Air Base Wing Public Affairs
Kirtland Air Force Base, NM --  When the final flight of the space shuttle Endeavour lifts off from NASA's John F. Kennedy Space Center, Cape Canaveral, Fla., on April 29, two experiments administered by the Air Force Research Laboratory's Space Vehicles Directorate will be housed in its cargo bay awaiting transfer to the International Space Station.

Three days after launch, Endeavour's robotic arm will move the AFRL payloads and another two experiments, the U.S. Naval Research Laboratory's Digital Imaging Star Camera and the U.S. Air Force Academy's Canary, to their new home during a two-to four-hour in-length process.

All four experiments reside in the STP-H3 payload, which was manifested, integrated and managed by the Department of Defense's Space Test Program office at NASA's Lyndon B. Johnson Space Center, in Houston, Texas.

Featuring the next generation of thermal control technology, the Massive Heat Transfer Experiment serves as a partnership between Northrop Grumman Corp., the DOD's STP, NASA's Goddard Space Flight Center, and AFRL.

With the dimensions of 2-feet by-feet high by three feet long, MHTEX, a one-year trial, will attempt to validate the employment of a capillary pump loop to cool a spacecraft eight times more efficiently than current systems.

"The MHTEX will be a great technology for the Air Force, as it will enable significant capabilities for the warfighter by providing the next generation of spacecraft with improved cooling," said Andy Williams, Thermal Systems lead, AFRL's Space Vehicles Directorate.

"The trial's goal will be to measure the on-orbit performance of the capillary pump loop in its efforts to significantly cool a structure by transferring heat to a radiator, which is not located near the heat source."

With an acronym that sounds familiar in another space galaxy, the second AFRL trial, Variable Emissivity Radiator; Aerogel Insulation Blanket; Dual Zone Thermal Control; Experiment Suite for responsive Space, or VADER, positioned directly below MHTEX, involves 10 separate coatings, manufactured by Eclipse Energy Systems, St. Petersburg, Fla.

When applying voltage or power to each coating, the emissivity changes and the process rejects more heat into space, similar to photo-grey or photo chromic sunglass lenses becoming darker when facing direct light.

This one-year experiment will also demonstrate spacecraft thermal control, as when the power has been turned off, each coating retains the heat.

A control system will monitor energy applied to the coatings, as well as the temperature of the payload. Another part of the VADER trial, the Aerogel Insulation Blanket, developed by Aspen Aerogels, Northborough, Mass., will cover the back of the experiment, directly behind the coatings. Similar to the MHTEX, data will be downloaded and processed at Kirtland Air Force Base. The information will ultimately be used to develop thermal control systems for future small satellites.

"VADER will have significant impact on smaller satellites. The experiment features an easy process, which will allow for cooling without a bunch of design and development," said Williams, who is also serving as the MHTEX and VADER Programs' manager.

"The whole purpose of the trial is to be robust and reconfigurable and to reduce the design and development of a satellite component from years to months to days."

The two other trials to also be placed on the ISS, the NRL's DISC and the USAFA's Canary, which will examine the interaction of approaching spacecraft with the background plasma environment around the ISS and disturbances in the ionosphere created by space vehicles, plus AFRL's experiments and orbital replacement units for the ISS will comprise a payload package weighing between 3,000 to 4,000 pounds.

"Of all the space missions I have participated in, this one is special since it involves the final flight of the space shuttle Endeavour. It is truly the end of an era, and flying the two AFRL experiments on the historic STS-134 mission is something I can tell my children and grandchildren about," Williams said.