Air Force begins testing newest AEHF satellite

by Scott Prater, 50th Space Wing Public Affairs

SCHRIEVER AIR FORCE BASE, Colo. (AFNS) -- Following a four-month journey, the second Advanced Extremely High Frequency satellite reached geosynchronous orbit Aug. 27.

The event is significant to the 4th Space Operations Squadron here because nearly 100 squadron members are now heavily involved in testing the vehicle.

The Space and Missile Systems Center in Los Angeles will continue to hold satellite control authority of AEHF-2 during the testing phase, then transfer satellite control authority to the 14th Air Force and 4th SOPS at a later date.

"During this testing phase, some capabilities require the use of AEHF-1, a 4th SOPS asset, hence the reason for the involvement of 4th SOPS personnel," said Lt. Col. Alistair Funge, 4th SOPS director of operations. "Our engineering shop, led by Maj. Yingwai Chan, is involved in day-to-day testing, coordinating ground support system time with the 22nd Space Operations Squadron and keeping leadership informed of ongoing activities."

First Lt. Peter Lusk explained that this testing is important not only for AEHF-2, but for the Milstar/AEHF constellation in general because of AEHF's expanded communications capability and performance compared to legacy Milstar satellites.

"Advanced Extremely High Frequency-1 has been cross linked in the Milstar constellation since 2011; however, now that there is a second AEHF satellite, we can use the full capabilities of their cross links," Lusk said.

As next generation communications satellites, AEHF vehicles hold eight times the capacity of Milstar vehicles.

The testing phase will present its own obstacles and challenges, but 1st Lt. Kathleen Giegler, 4th SOPS payload engineer, explained that doing so while the satellite is on orbit represents a vital step toward gaining operational acceptance.

"It's almost impossible to test these types of satellites on the ground because of how they'll be cross linked together and how they will interact in space," Giegler said. "It promises to be a new experience for all involved. But one thing is certain, once AEHF-2 is fully operational, the survivable secure and jam resistant communications for the U.S. military and national leadership will have received a significant upgrade."

While 4th SOPS crews work with their counterparts at SMC and contractor Lockheed Martin to test the vehicle, the teams also must integrate AEHF-2 into the Milstar/AEHF constellation.

"This transition process worked well with AEHF-1 and we expect it to be just as smooth with AEHF-2," Funge said. "This way, 4th SOPS crews and engineering support staff will also get hands-on experience with AEHF-2 during these activities. Throughout the test period, 4th SOPS members will monitor the constellation using our in-band Advanced Satellite Mission Control Subsystem and Space-Ground Link System as well as perform routine and test related operations."

Four satellites are currently planned to complete the AEHF constellation. The third AEHF satellite is tentatively scheduled for launch in 2013.

Military satellite relying on backup plan to save itself

A rescue plan is being implemented to salvage the U.S. military's pricy new communications satellite despite a serious malfunction that knocked out its main engine and stymied the craft's maneuvering ability.

The Advanced Extremely High Frequency 1 spacecraft was launched into a preliminary orbit by an Atlas 5 rocket on August 14 from Cape Canaveral, Florida.

A day after launch during the initial orbit raising burn when the satellite's main engine shut down shortly after ignition for still-unexplained reasons. Another attempt tried August 17 also ended immediately when the engine again failed to generate the expected acceleration.

A makeshift plan has been developed to salvage the mission and AEHF 1 could reach the desired geosynchronous orbit sometime next summer, 7 to 9 months later than scheduled.

You can read more details on this story at
http://www.spaceflightnow.com/atlas/av019/100830orbit.html

Air Force team launches first advanced satellite

by 1st Lt. Karl Wiest, 45th Space Wing Public Affairs

CAPE CANAVERAL AIR FORCE STATION, Fla. (AFNS) -- A team from the 45th Space Wing successfully launched the first Advanced Extremely High Frequency satellite onboard an Atlas V launch vehicle from Launch Pad 41 here Aug. 16 at 7:07 a.m.

"This is an historic launch of an important asset to our nation's military and our allies," said Undersecretary of the Air Force Erin C. Conaton. "The AEHF satellite will provide secure, protected communications capability across the spectrum of mission areas, including land, sea and air warfare. Its benefits will be felt in special operations, strategic nuclear deterrence, strategic defense, theater missile defense and space operations and intelligence.

"The 45th Space Wing and the Space & Missile Systems Center deserve praise for their great work," she said, "and I also applaud the teamwork between the Air Force and its partners involved in making this mission a success."

The commander of the 45th Space Wing also praised the work involved in making this launch a success.

"We have an outstanding launch team assembled here on the Space Coast that truly sets the standard for others to follow; it has been a privilege to work on this mission," said Brig. Gen. Ed Wilson.

The 45th Space Wing's mission is to assure access to the higher frontier and to support global operations by delivering space effects that protect and defend the nation through global vigilance, reach and power.

DoD AEHF-1 Launch Scheduled for Tomorrow

According to Kevin Fetter on the SEESAT newsgroup, the first AEHF communications satellite is scheduled for launch tomorrow Aug 14 between 1106-1306 UTC.

I have complete details on this satellite in a previous post here on the MMP at
http://mt-milcom.blogspot.com/2010/08/aehf-1-milsat-may-launch-next-week.html

You can download the launch mission book in pdf at http://www.ulalaunch.com/site/docs/missionbooklets/AV/av_aehf1_mob.pdf

There will be a webcast of the Atlas launch at http://mfile.akamai.com/29730/live/reflector:58048.asx?bkup=58227

AEHF-1 Milsat may launch next week

According to an article on SpaceFlight now, the AEHF-1 Milsat is scheduled to launch next week, August 12, and will be tested at an on orbit geo location of 90 degrees west.

The advanced satellite that will be used for relying secure US military communications will be launched on an Atlas 5 (5-531 configuration) rocket from Cape Canaveral AS, Florida. Liftoff had been targeted for August 12 at 7:14 a.m. EDT, but the launch could be sliding a day or two.

This maiden AEHF bird should be ready, if all goes well, to enter service early next year from an orbital location dictated by the needs at that time, officials said.

"AEHF will provide tactical and strategic support to a wide variety of Army, Navy, Marine and Air Force users," said Col. Michael Sarchet, commander of the Protected Satellite Communications Group at the Space and Missile Systems Center.

The U.S. military purchased a series of AEHF satellites for launches in the coming years to replace the aging Milstar communications spacecraft that link the national leadership and warfighters. The Advanced EHF Program is the next generation of global, highly secure, survivable communications system within all services of the Department of Defense.

"AEHF is a very sophisticated satellite because it is built to provide the highest levels of protection for our nation's most critical users. Encryption, low probability of intercept and detection, jammer resistance and the ability to penetrate the electro-magnetic interference caused by nuclear weapons are essential features when communication can be of the highest priority," Sarchet said.

In Nov. 2001, the U.S. Air Force awarded Lockheed Martin Space Systems and Northrop Grumman Space Technology (Formerly TRW Space & Electronics) a $2.698 billion contract to begin the System Development and Demonstration (SDD) phase of the Advanced Extremely High Frequency (Advanced EHF) Program.

The SDD phase will deploy two Advance EHF satellites and the Advance EHF mission control segment. The new mission control segment will support both Milstar and AEHF. Lockheed Martin will serve as the developer of the ground segment, satellite bus provider, space vehicle integrator and overall systems integrator and prime contractor. This role builds on Lockheed Martin's successful experience on Milstar and DSCS. Northrop Grumman will provide the payload and associated components (digital processor and RF equipment).

The MILSATCOM Program Office, located at the Space and Missile Systems Center, Los Angeles Air Force Base, Calif., is the Advanced EHF contract manager and lead agency for ensuring the secure communications capabilities of this system are made available to the warfighter.

The Advanced EHF Program is the follow-on to the DoD's Milstar highly secure communication satellite program, which currently has a four-satellite operational constellation. The last Milstar satellite was successfully launched in April 2003.

As envisioned by the Pentagon, the fully operational Advanced EHF constellation will consist of four crosslinked satellites providing coverage of the Earth from 65 degrees north latitude to 65 degrees south. These satellites will provide more data throughput capability and coverage flexibility to regional and global military operations than ever before. A fifth satellite built could be used as a spare or launched to provide additional capability to the envisioned constellation.

Advanced EHF satellites will provide 10 times greater total capacity and offer channel data rates six times higher than that of Milstar II communications satellites. The higher data rates permit transmission of tactical military communications such as real-time video, battlefield maps and targeting data.

To accomplish this, Advanced EHF adds new higher data rate modes to the low data rate and medium data rate modes of Milstar II satellites. The higher data rate modes will provide data rates up to 8.2 million bits of data per second (Mbps) to future Advanced EHF Army terminals. That rate is more than 150 times faster than the 56 kilobit-per-second modems of today's personal computers. Each Advanced EHF satellite employs more than 50 communications channels via multiple, simultaneous downlinks. For global communications, the Advanced EHF system uses inter-satellite crosslinks, eliminating the need to route messages via terrestrial systems.



U.S. Air Force Fact Sheet
Advanced Extremely High Frequency (AEHF) System

Mission/Vision

The Advanced Extremely High Frequency (AEHF) System is a joint service satellite communications system that will provide survivable, global, secure, protected, and jam-resistant communications for high-priority military ground, sea and air assets. Advanced EHF will allow the National Security Council and Unified Combatant Commanders to control their tactical and strategic forces at all levels of conflict through general nuclear war and supports the attainment of information superiority.

Background

The AEHF System is the follow-on to the Milstar system, augmenting and improving on the capabilities of Milstar, and expanding the MILSATCOM architecture. AEHF will provide connectivity across the spectrum of mission areas, including land, air and naval warfare; special operations; strategic nuclear operations; strategic defense; theater missile defense; and space operations and intelligence.

Features

Part of the MCSW's Protected SATCOM Group, the system consists of four satellites in geosynchronous earth orbit (GEO) that provides 10 times the throughput of the 1990s-era Milstar satellites with a substantial increase in coverage for users. First launch in late 2010, AEHF will provide continuous 24-hour coverage between 65 degrees north and 65 degrees south latitude. The AEHF system is composed of three segments: space (the satellites), ground (mission control and associated communications links) and terminals (the users). The segments will provide communications in a specified set of data rates from 75 bps to approximately 8 Mbps. The space segment consists of a cross-linked constellation of three satellites. The mission control segment controls satellites on orbit, monitors satellite health and provides communications system planning and monitoring. This segment is highly survivable, with both fixed and mobile control stations. System uplinks and crosslinks will operate in the extremely high frequency (EHF) range and downlinks in the super high frequency (SHF) range. The terminal segment includes fixed and ground mobile terminals, ship and submarine terminals, and airborne terminals used by all of the Services and international partners (Canada, Netherlands and UK). MCSW is responsible for acquisition of the space and ground segments as well as the Air Force terminal segments. The Army and Navy will acquire their own terminals.

General Characteristics

Primary Function: Near-worldwide, secure, survivable satellite communications
Primary Contractor: Lockheed Martin Space Systems Company
Payload: Onboard signal processing, crossbanded EHF/SHF communications
Antennas: 2 SHF Downlink Phased Arrays, 2 Crosslinks, 2 Uplink/Downlink Nulling Antennas, 1 Uplink EHF Phased Array, 6 Uplink/Downlink Gimbaled Dish Antenna, 1 Each Uplink/downlink earth coverage horns
Capability: Data rates from 75 bps to approximately 8 Mbps