TacSat-1
{{Use American English|date=April 2021}}
{{Use dmy dates|date=April 2021}}
{{Infobox spaceflight
| name = TacSat-1
| names_list = TacSat-1A
| image = TacSat-1.jpg
| image_caption = TacSat-1 imaging satellite
| image_size = 300px
| mission_type = Technology, Communications
| operator = United States Naval Research Laboratory
| COSPAR_ID =
| SATCAT =
| website =
| mission_duration = 1 year (planned)
Never launched
| spacecraft = TacSat
| spacecraft_type =
| spacecraft_bus = MicroStar (triple)
| manufacturer = Orbital Sciences Corporation
| launch_mass = {{cvt|108|kg}}
| dry_mass =
| dimensions =
| power =
| launch_date = 2007 (Never launched)
| launch_rocket = Falcon 1
| launch_site = Omelek Island
| launch_contractor = SpaceX
| entered_service = Never launched
| disposal_type =
| deactivated =
| last_contact =
| orbit_reference = Geocentric orbit (planned)
| orbit_regime = Low Earth orbit
| orbit_altitude = {{cvt|500|km}}
| orbit_inclination = 64.0°
| orbit_period = 90.0 minutes
| apsis = gee
| insignia =
| insignia_caption =
| insignia_size = 200px
| programme = TacSat series
| previous_mission =
| next_mission = TacSat-2
}}
TacSat-1 was an experimental satellite built by the Naval Research Laboratory (NRL) on behalf of the United States Department of Defense (DoD) Office of Force Transformation (OFT). It was the planned payload of the sixth launch of the SpaceX Falcon 1.{{cite web|url=http://hobbyspace.com/nucleus/index.php?itemid=8333 |title=Next Falcon 1 launch planned within 2 weeks|first=Clark S.|last=Lindsey|publisher=HobbySpace|work=RLV and Space Transport News|date=2008-09-11|access-date=2008-09-13|url-status=dead|archive-url=https://web.archive.org/web/20110712213647/http://hobbyspace.com/nucleus/index.php?itemid=8333|archive-date=2011-07-12}} It was however never launched into space. The second satellite in the series, TacSat-2, launched before TacSat-1 and this led to the cancellation of TacSat-1's launch.
TacSat-1 would have carried a variety of experimental payloads.{{cite web|url=http://www.nrl.navy.mil/content.php?P=04REVIEW207|title=Tactical Microsatellite Experiment (TacSat-1)|publisher=NRL|url-status=dead|archive-url=https://web.archive.org/web/20080314224411/http://www.nrl.navy.mil/content.php?P=04REVIEW207|archive-date=2008-03-14}} Much of the payload software was implemented through the use of bash scripts operating on the "Copperfield-2" general-purpose computer system aboard the spacecraft.{{cite web|url=http://www.nrl.navy.mil/content.php?P=04REVIEW212|title=Rapid Satellite Payload Development for TacSat-1|publisher=NRL|url-status=dead|archive-url=https://web.archive.org/web/20070504140245/http://www.nrl.navy.mil/content.php?P=04REVIEW212|archive-date=2007-05-04}} {{PD-notice}}
Purpose
The TacSat series of experimental spacecraft are designed to allow military commanders on a battlefield to request and obtain imagery and other data from a satellite as it passes overhead. Collected data will be delivered to field commanders in minutes rather than hours or days. The sensor on TacSat-1 could collect color images sharp enough to distinguish ground objects as small as 1 meter in diameter.{{cite news|last=Singer|first=Jeremy|url=http://www.defensenews.com/story.php?F=2395306&C=airwar|archive-url=https://archive.today/20120724124219/http://www.defensenews.com/story.php?F=2395306&C=airwar|url-status=dead |archive-date=2012-07-24|title=USAF To Experiment With Satellite To Improve Ground Communications|publisher=Defense News|date=2006-12-04}}
Launch
TacSat-1 was initially planned for launch in January 2004, but delays in Falcon 1 becoming operational precluded this date. It was initially scheduled to fly on the maiden flight of the Falcon 1, but technical problems led to another Falcon 1, with FalconSat-2, launching first. Following the failure of this launch, it was moved to the third flight, to allow a demonstration launch to precede it. The failure of the demonstration flight led to further delays. In August 2007, the Pentagon announced that the launch of TacSat-1 was canceled due to the completion of most of its mission requirements by AFRL's previously launched TacSat-2.{{cite web|url=https://spacenews.com/pentagon-cancels-tacsat-1-mission/|title=Pentagon Cancels TacSat-1 Mission|last=Berger|first=Brian|date=2007-09-06|publisher=Space News|access-date=2022-12-10}} In September 2008, this decision was reversed, and it was reported that TacSat-1 would be launched by the sixth Falcon 1, in 2009, and be called TacSat-1A. This revamped mission was later cancelled again when TacSat-2 proved all the things TacSat-1 was supposed to.{{cite web|url=https://space.skyrocket.de/doc_sdat/tacsat-1.htm|title=TacSat 1A|publisher=Gunter's Space Page|date=22 February 2018|access-date=19 April 2021}}
Systems
The TacSat series of satellites use commercial or available launchers, and largely off-the-shelf components, in order to reduce costs.
= Satellite bus =
The TacSat-1 spacecraft was based on Orbital Sciences Corporation (OSC) MicroStar (triple) satellite bus, also used for the Orbcomm communications constellation. TacSat-1 inherited its avionic bus from an unlaunched Orbcomm-satellite.
Developers
Apart from the Naval Research Laboratory (NRL), other organizations participating included:
References
{{Portal|Spaceflight}}
{{Reflist|30em}}
{{TacSat}}
{{AFRL spacecraft}}