Home >> July 2010 Edition >> Insight... Alternatives To Dedicated Space Platforms
Insight... Alternatives To Dedicated Space Platforms
author: Scott Smith, Executive Vice President, Iridium Communications Inc.

Economic realities dictate that the satellite industry will probably be facing a short-term future characterized by budget cuts and delays in government-funded space programs. There is growing concern among many in the Earth sciences community that this may result in significant gaps in the collection of critical climate observation data in the next few years. Likewise, the government and military sector face the increased likelihood of service gaps in several important mission areas.

iridium next sm 070810 In this uncertain climate, we are seeing increased interest in hosted payloads on commercial satellites, which can provide a lower-cost and timely alternative to dedicated Earth observation satellites. Iridium’s planned replenishment program to replace the existing 66 low-Earth orbiting (LEO) communication satellites, in particular, poses a unique opportunity for piggy-backing Earth observation sensors as secondary payloads on the new spacecraft. Iridium NEXT will be the largest satellite launch program of the decade, creating an unprecedented opportunity that will not be repeated for a long time to come.

On June 2, Iridium awarded a contract to Thales Alenia Space for the design and construction of the Iridium NEXT satellites, and announced that Coface, the French export credit agency, has issued, for the account of the French State, a “Promise of Guarantee” which commits to cover 95 percent of the $1.8 billion credit facility for the project. The financing to be covered by the Coface guarantee is being syndicated through French and other major international banks and financial institutions, and is expected to be completed this summer. Launches are scheduled to start in the first quarter of 2015.

miteq ad sm 070810 To be certain, the concept of secondary mission payloads on Iridium satellites is not new. The National Science Foundation and Johns Hopkins University Applied Physics Laboratory have long used magnetometer data from existing Iridium satellites and recently completed initial trials using enhanced samplings of the magnetometers to provide 24/7 real-time acquisition and processing of magnetic field measurements in space. The program, called the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE), aims to improve monitoring and forecasting space weather to help safeguard technologies, such as GPS navigation and positioning, which can be adversely affected by geospace storms.

Interest in hosting payload on NEXT was affirmed by scientists and space agencies in a meeting that took place in January 2008 at the Royal Society in London. It included representatives from Iridium, the international environment and climate science communities, U.S. and European weather and space agencies and the aerospace industry. Concerned by the growing danger of data gaps in key Earth observation programs, they reached a consensus that the LEO constellation, with its global coverage, low latency and cross-linked satellite network architecture, could offer truly impressive temporal and spatial coverage for monitoring critical variables in climate and environment change in a very cost-effective manner.

Since then, various teams of scientists from groups such as the NASA/Jet Propulsion Laboratory, the Rutherford Appleton Laboratory and Centre National d’Études Spatiales (CNES) have conducted independent studies under the auspices of the Group on Earth Observations (GEO) validating the feasibility of using the Iridium NEXT satellites to host Earth observation and remote sensing payloads.

Specific feasibility studies have examined radar altimeters for monitoring the height of sea surface, waves and ice; broadband radiometers for measuring Earth’s radiation budget; multi-spectral imagers to detect ocean color and land imaging, key measures for monitoring deforestation, desertification and agricultural crops; and GPS radio occultation measurements to provide data on atmospheric humidity and temperature profiles.

iridium d1 sm 070810

Other potential mission areas include ozone profile monitoring, solar irradiance, polar wind observations and forest fire detection. In addition, several national weather and climate agencies have conducted feasibility studies for specific mission payloads on Iridium NEXT.

Importantly, all of these missions support the aims and objectives of the Global Earth Observation System of Systems (GEOSS), which emphasize international cooperation, data sharing and informed decision-making for the benefit of the public as well as the private sector.

In addition to the Earth sciences community, the government and military sectors are also looking to hosted payloads on Iridium NEXT satellites to address a variety of near-term and long-term government and military requirements. Potential missions include dedicated communications, signals collection, space weather and space situational awareness. Iridium NEXT, it is thought, can provide the necessary combination of coverage, persistence and economy that can help fill the critical gap until the next generation of major dedicated satellite programs can be deployed.

By leveraging commercial satellite assets, mission payloads can be sent into space at a fraction of the capital and operational costs associated with developing and deploying mission-specific dedicated satellites and the infrastructure required to support them. A recent study by Futron Corporation (see chart) compared annualized costs for various sensor missions flown in the past with what they might cost as a hosted payload on Iridium NEXT. The bottom line showed that the average costs of using the commercial satellites were less than 25 percent of the expense for a dedicated mission.

This private-public partnership presents a unique opportunity to deploy a wide range of payloads into space, but there is a narrow window. For payloads to be deployed with the planned first round of launches in early 2015, it will be necessary to make a commitment by next year. Now that the contract has been awarded to Thales Alenia Space, we are moving forward with an aggressive timetable for full design and development — the time to act is now.