The second mission of 2015 for SpaceX’s Falcon 9 rocket finally thundered into space today from Space Launch Complex 41 at Cape Canaveral after three days of delays due to weather and technical issues. Described as the most beautiful Falcon launch to date, the vehicle lifted off a few minutes before sunset at 6:03:32 pm EST and painted the sky in vibrant hues of red, yellow and orange on its way to deliver the NOAA/NASA Deep Space Climate Observatory to its distant perch between the Earth and Sun.
Boosted by nine Merlin 1D engines in its first stage producing a combined thrust of 1.3 million pounds, the Falcon 9 v1.1 launch marked the beginning of SpaceX’s most distant mission yet and the first into interplanetary space. DSCOVR’s destination at the
Sun-Earth L1 Lagrange Point lies nearly one million miles away from Earth and will provide DSCOVR with a continual view of the sunlit side of Earth. Its vantage point between Earth and Sun will enable the spacecraft’s instruments to detect, observe and provide advance notice of space weather events that could affect Earth and satellites in orbit around the planet, including the International Space Station.
While the primary objective of the Falcon 9 mission was met perfectly – delivery of DSCOVR to orbit – SpaceX was unable to conduct another first stage soft landing attempt. The first stage return test would have been more challenging than previous attempts due to the deep space nature of the Earth-Sun L1 launch trajectory for DSCOVR. Deceleration forces were anticipated to be twice as high with heating along the exterior airframe to be four times at high as the last attempt on Flight 14.
As it turned out, the same weather system that forced one launch postponement created rough conditions at sea on launch day, making it futile to try landing the rocket on the 300 ft × 160 ft autonomous drone ship named “Just Read The Instructions”.
According to SpaceX, the ship was being called back to port due to “waves reaching up to three stories in height crashing over the decks”. Additionally, one of the four thrusters which keep the barge in a constant position had malfunctioned, making station-keeping difficult.
As noted, DSCOVR is bound for the L1 Lagrange point between the Earth and Sun. Nearly a million miles from Earth, the mission marks the most distant target achieved by Falcon as well as SpaceX’s first launch into interplanetary space. Orbiting around L1, DSCOVR will maintain a relatively stable position between the Sun and Earth and will have a nearly continuous view of the daylit side of the planet.
The Lagrange points (technically called libration points) are the five orbital positions where a small spacecraft or other body affected only by gravity can maintain a stable configuration with respect to two much more massive larger objects such as the Sun and Earth or Earth and Moon. The Lagrange points mark positions where the combined gravitational pull of the two large masses are in equilibrium and provide precisely the centripetal force necessary for the small object to orbit with them.
The L1 point lies on a line defined by the two large masses, and directly in between them. At this point, the gravitational pull from each of the larger objects is directly opposed to the other and partially or wholly cancel it out.
The L1 point is the most easiest to understand for the layman. “An object that orbits the Sun more closely than Earth would normally have a shorter orbital period than Earth, but that ignores the effect of Earth’s own gravitational pull. If the object is directly between Earth and the Sun, the Earth’s gravity weakens the Sun’s pull on the object, and therefore increases the orbital period of the object. The closer to Earth the object is, the greater this effect is. At the L1 point, the orbital period of the object becomes exactly equal to Earth’s orbital period. L1 is about 1.5 million kilometers from Earth.” (WIkipedia http://en.wikipedia.org/wiki/Lagrangian_point)
Sun–Earth L1 is suited for making observations of the Sun–Earth system. Objects here are never shadowed by Earth or the Moon. The first mission of this type was the International Sun Earth Explorer 3 (ISEE-3) mission used as an interplanetary early warning storm monitor for solar disturbances.
International Sun Earth Explorer 3 (ISEE-3) began its mission at the Sun–Earth L1 before leaving to intercept a comet in 1982. The Sun–Earth L1 is also the point to which the Reboot ISEE-3 mission was attempting to return the craft as the first phase of a recovery mission (as of September 25, 2014 all efforts have failed and contact was lost). Solar and Heliospheric Observatory (SOHO) is stationed in a halo orbit at L1 , and the Advanced Composition Explorer (ACE) in a Lissajous orbit, also at the L1 point. WIND is also at L1 .
When it reaches its final orbit and completes its checkout phase about 110 days from now, DSCOVR will take over from the 17 year-old ACE scientific satellite as the primary early warning satellite for solar magnetic storms that could impact Earth. Flying alongside the ACE research spacecraft, DSCOVR will be the United States’ first operational craft in deep space.
“Located in line between the sun and the Earth, DSCOVR will be a point of early warning whenever it detects a surge of energy that could trigger a geomagnetic storm destined for Earth,” said Stephen Volz, Ph.D., assistant administrator for NOAA’s Satellite and Information Service. “According to the National Academies of Sciences, a major solar storm has the potential to cost upwards of $2 trillion, disrupting telecommunications, GPS systems, and the energy grid. As the nation’s space weather prediction agency, when DSCOVR is fully operational and our new space weather forecast models are in place, we will be able to provide vital information to industries and communities to help them prepare for these storms.”
DSCOVR’s Science Payload
DSCOVR weighs approximately 1250 lb at launch encapsulated in a body 54 inches by 72 inches. The spacecraft bus is equipped with two deployable solar arrays, a propulsion module, boom, and high-gain antenna. It carries three primary science instruments: the Sun observing Plasma-Magnetometer (PlasMag) and Earth observing NISTAR and EPIC.
PlasMag will measure solar wind activity and the behavior of solar wind particles. It is a suite consisting of three parts: 1) a fluxgate vector Magnetometer, 2) a Faraday Cup solar wind positive ion detector and 3) a top-hat Electron Spectrometer.
The magnetometer will measure the three-dimensional magnetic field vector of the solar wind. The Faraday Cup will measure properties of solar wind in three dimensions. This data will allow the investigation of solar wind waves and turbulence at unprecedented time resolution. The “top-hat” electron electrostatic analyzer was re-calibrated and relocated on the spacecraft in 2013. It will provide high time resolution solar wind electron observations.
National Institute of Standards and Technology Advanced Radiometer (NISTAR) is a cavity radiometer designed to measure the absolute spectral irradiance (power of electromagnetic radiation) reflected and emitted from the entire sunlit face of the Earth.
The Earth Polychromatic Imaging Camera (EPIC) is an imager that provides global spectral images of the entire sunlit face of Earth and insight into Earth’s energy balance. It will measure ozone amounts, aerosol amounts, cloud height and phase, vegetation properties, hotspot land properties and UV radiation estimates at Earth’s surface.
DSCOVR’s Political Past
DSCOVR has a somewhat storied history. Ostensibly conceived in a dream by former Vice President Al Gore, the mission was first proposed in 1998 as a way to inspire people around the world while also conducting scientific observations. Originally named Triana after Rodrigo de Triana, the first of Christopher Columbus’s crew to sight land in the Americas, the spacecraft would provide nearly continuous views of the sunlit side of Earth and stream them in near real-time over the internet.
“This new satellite, called Triana, will allow people around the globe to gaze at our planet as it travels in its orbit around the sun for the first time in history,” Vice President Gore said. “With the next millennium just around the corner, developing this High Definition TV quality image of the full disk of the continuously lit Earth and making it available 24 hours a day on the Internet will awaken a new generation to the environment and educate millions of children around the globe.”
The inspiration for the mission came from the famous “Blue Marble” photo of Earth from Apollo 17.
“In the history of space exploration there are only a few photographs of the full earth that have resonated with the public. Christmas 1968 was an epiphany for many Americans, when they first saw the image ‘Earth Rising,’” said Gore. “It is considered one of the fundamentally profound images of this century. Another photograph, “The Blue Marble” taken in 1972 during Apollo 17, began an era of global awareness.”
“These images of the earth moved thousands of Americans and encouraged them to become active stakeholders in our planet’s well being. As we connect all our classrooms to the Internet, we have the opportunity to bring new education and potential scientific projects as well as global weather observations to millions of American classrooms and living rooms via television and computer.”
In addition to an imaging camera, Triana was to carry a radiometer would take the first direct measurements of how much sunlight is reflected and emitted from the whole Earth. Over time, the scientific goals were expanded expanded to measure the amount of solar energy reaching Earth, cloud patterns, weather systems, vegetation, and track the amount of ultraviolet light penetrating Earth’s ozone layer and reaching the surface.
Almost immediately, Triana was thrown into a political firestorm, with critics – mostly climate change skeptics and Republicans opposed to the Clinton Administration – attacking the proposal and mockingly referring to Triana as “GoreSat.”
A 1999 report by NASA’s Inspector General reported that “the basic concept of the Triana mission was not peer reviewed”, and “Triana’s added science may not represent the best expenditure of NASA’s limited science funding.” Following the contested election of 2000, the Bush Administration put the project on hold shortly after George W. Bush’s inauguration. Meanwhile, Congress asked the National Academy of Sciences whether the project was worthwhile, whose report stated that the mission was “strong and scientifically vital.”
Rapidly increasing mission costs became a concern as well as NASA sought to include more and more science into Triana.
“In the context of NASA’s constrained budget and the widespread availability of satellite pictures of the Earth, we are concerned about the cost and changing goals of the Triana mission,” stated the NASA IG report. “A relatively simple and inexpensive mission focused primarily (though not exclusively) on inspiration and education has evolved into a more complex mission focused primarily on science.”
“The added scientific capabilities will increase the amount of data gathered by the mission, but they will also increase the mission’s total cost.”
When it was announced, Triana was supposed to cost close to $20 million, with a cap of $50 for the mission. When NASA added additional instruments, the budget necessarily increased to $77 million.
Triana was slated to fly on STS-107, the tragic final mission of space shuttle Columbia. When politics and questions prompted NASA to pull the mission from the manifest, the spacecraft was put in long-term storage.
The spacecraft was pulled from storage in November 2008 for a possible future launch. NASA renamed the satellite Deep Space Climate Observatory (DSCOVR).
In February 2011, the Obama administration attempted to secure funding to re-purpose the DSCOVR spacecraft as a solar observatory to replace the aging Advanced Composition Explorer (ACE) spacecraft. Mission cost again escalated. This was driven by changes to the spacecraft due to the change of launch vehicle from the space shuttle to a Delta II or Falcon 9, refurbishment and upgrading its instruments, and the higher cost of an ELV launch. At the time of its launch, more than 16 years after it was proposed, the total mission cost was pegged by program managers at $340 million – almost 700% higher than the original $50 million budget.
The DSCOVR mission is a joint effort by NOAA and NASA, led by NOAA, with launch services directed by the U.S. Air Force. NASA received funding from NOAA to refurbish the DSCOVR spacecraft and its solar wind instruments, develop the command and control portion of the ground segment, and manage launch and activation of the satellite. The Air Force funded and managed the Falcon 9 launch services for DSCOVR.
Notably, this was the first Falcon 9 mission launched for the Department of Defense. Official note that the DSCOVR launch also served as a good test for SpaceX’s ability to execute a DoD mission and thereby aiding the company’s efforts to complete Air Force EELV program certification.