UPDATE 9:00pm Eastern June 24: SpaceX has delayed tonight’s planned launch from 11:30pm to ‘No Earlier Than’ 2:30am Eastern time.
ORIGINAL STORY: For the third time in 16 months, SpaceX is readying the most powerful rocket in its fleet—the tripled-cored Falcon Heavy—to launch from historic Pad 39A at the Kennedy Space Center (KSC) in Florida. Scheduled to fly late Monday night, 24 June, the giant booster, whose 27 Merlin 1D+ first-stage engines produce approximately 5.1 million pounds (2.3 million kg) of propulsive yield, will launch the multi-faceted STP-2 mission for the Department of Defense Space Test Program.
The rocket is scheduled to fly due East from the Florida spaceport during a four-hour “window” extending from 11:30 p.m. EDT Monday through 3:30 a.m. EDT Tuesday, 25 June. It will mark the Falcon Heavy’s first flight in the hours of darkness, and will also build upon the test-flight experience gained during its two previous launches to trial the capability of reflying the same side boosters (B1052 and B1053) from its most recent launch last April.
The mission also marks the first multi-payload, multi-orbit flight for the Falcon Heavy, and the first DOD mission on SpaceX’s newest rocket.
A customary Static Fire Test of the booster’s 27 engines was conducted late on Wednesday 19 June, after which SpaceX declared via Twitter its readiness to support a launch overnight on the 24th/25th.
“We’re thrilled about the upcoming STP-2 mission,” said Lt. Gen. John F. Thompson, SMC commander and Air Force program executive officer for Space. “It’s an exciting partnership with NASA, NOAA and SpaceX to provide space access for important military and civil experiments while demonstrating the Falcon Heavy launch vehicle capabilities for future operational National Security Space missions. The STP-2 mission exemplifies our SMC 2.0 transformation—we’re pursuing innovative new ways to deliver space capabilities for the Air Force and the Defense Department.”
Three missions by such a large vehicle in the span of little more than a year is an impressive accomplishment, particularly when one considers the tumultuous gestation of the Falcon Heavy. Formally unveiled as a concept almost a decade ago, SpaceX CEO Elon Musk later acquiesced that the intricacy of creating a triple-cored launcher was more than strapping three “single-stick” Falcon 9s together. Early plans envisaged the debut of the rocket in 2013 or 2014, with the first flight slated for Vandenberg Air Force Base, Calif.
In spite of initial doubts about the Heavy’s capability, SpaceX secured a 20-year lease of Pad 39A in April 2014, with an expectation that the Apollo-era launch complex—whose first flight in November 1967 had seen the maiden voyage of the Saturn V—would serve as a foundation for some of the Heavy’s early missions. Agonizingly, the booster fell further and further behind schedule, with its initial launch always seemingly slated to occur “this year”, yet continually slipping inexorably to the right.
At length, late in 2017, Mr. Musk revealed the first images of actual Falcon Heavy hardware being readied in the horizontal integration facility, near Pad 39A, and in February 2018—witnessed by a huge internet audience, in YouTube’s second-most-watched livestream—the vehicle which had been the butt of cruel humor for so many years finally proved the naysayers wrong and took flight at last. With the test flight done and Mr. Musk’s cherry-red Tesla Roadster headed smoothly onto a Mars-crossing trajectory, the serious work of bringing the Falcon Heavy to operational status with a commercial launch entered high gear. Last April, the roar of 27 Merlin 1D+ engines echoed across Florida once again and Saudi Arabia’s heavyweight Arabsat 6A communications satellite was beautifully launched on the first leg of its journey to geostationary altitude.
However, to date, the safe return to port of all three boosters—the core and the two side-mounted rockets—has eluded SpaceX. In February 2018, both sides landed smoothly at LZ-1 and LZ-2, whilst the core failed to touch down on the Autonomous Spaceport Drone Ship (ASDS), “Of Course I Still Love You”, offshore in the Atlantic Ocean. Fourteen months later, again, the side boosters made perfect, on-point LZ-1 and LZ-2 touchdowns and the core succeeded in alighting onto the ASDS. However, during its transfer back to Port Canaveral, oceanic swells caused it to shift and eventually topple over. It is hoped that during this weekend’s third flight of the Falcon Heavy, long-deserved success will finally be achieved. Current plans are for the B1052 and B1053 side boosters to land at LZ-1 and LZ-2 and the never-before-flown B1057 core to return to the drone ship – some 1,240km downrange – further than any previous landing attempt.
Back in December 2012, SpaceX announced that it had signed contracts (reportedly worth $165 million) with the Air Force Space and Missile Systems Center (SMC), headquartered at Los Angeles Air Force Base in El Segundo, Calif., to launch the multi-faceted STP-2 payload aboard a Falcon Heavy in the “mid-2015” timeframe. STP-2 includes around 24 small spacecraft, to be delivered into four discrete orbital locations, requiring four upper-stage “burns” by the Falcon Heavy. When the contracts were signed, they represented the first Evolved Expendable Launch Vehicle (EELV)-class missions awarded to SpaceX at the time.
“SpaceX deeply appreciates and is honoured by the vote of confidence shown by the Air Force in our Falcon launch vehicles,” Mr. Musk said at the time of the contract award. “We look forward to providing high-reliability access to space with lift capability to orbit that is substantially greater than any other launch vehicle in the world.”
The cargo includes the six-strong Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC)-2 cluster of satellites, also known as “Formosat-7”, which follows on from the Formosat-3 mission, launched via a Minotaur booster back in April 2006. Formosat-3 was intended to advance research in meteorology, ionospheric physics, climatology, geodesy and space weather. As its immediate successor, Formosat-7’s six satellites will be emplaced into six separate orbital planes, some 60 degrees apart.
Part of a joint venture between the National Space Organization of Taiwan (NSPO) and the National Oceanic and Atmospheric Administration (NOAA), it is expected to surpass Formosat-3 by a fivefold increase in data-gathering precision and number of measurements. The Air Force is partnering on COSMIC-2 and has provided a Radio Frequency (RF) beacon transmitter and Velocity, Ion Density and Irregularities (VIDI) instrument aboard each satellite. Original plans called for COSMIC-2 to include as many as 12 satellites, launched in batches of six, with a second flight into a higher-inclination orbit in 2020. However, in October 2017 a lack of funding caused the COSMIC-2B element to be canceled.
The primary payload aboard the COSMIC-2 satellites is a tri-band Global Navigation Satellite System-Radio Occulation (GNSS-RO) receiver, which will collect more soundings per receiver by adding tracking capability from Europe’s Galileo system and Russia’s Global Navigation Satellite System (GLONASS). This is expected to yield higher spactial and temporal densities in the COSMIC-2 data, with correspondingly greater usefulness in weather prediction modeling and severe weather forecasting. Taiwan is also furnishing a dual-band radio beacon scintillation instrument for ionospheric observations and an ion velocity monitor as part of COSMIC-2’s science payload.
When operational, COSMIC-2 is expected to produce over 8,000 sounding profiles daily with each 600-pound (277.8 kg) satellite planned to remain operational in its 300-mile-high (500 km) orbit for at least five years.
Elsewhere aboard the Falcon Heavy is the Air Force Research Laboratory’s 1,100-pound (500 kg) Demonstration and Science Experiments (DXS), bound for a higher Medium Earth Orbit (MEO) at 3,700 miles (6,000 km) x 7,400 miles (12,000 km). It will explore the deployment, dynamics, control and environmental degradation of large deployable structures, evaluate the performance and radiation tolerance of thin-film photovoltaics and the behaviour of energetic particles and plasmas at MEO altitude.
Other payloads include an Air Force Academy solar telescope equipped with a unique sieve-like optic membrane, a Naval Postgraduate School nanosatellite for space weather observations and technology demonstrations, a pair of Naval Research Laboratory CubeSats connected by a half-mile-long (1 km) electrodynamic tether for orbit-adjustment tests and the Naval Academy’s PSat-2 two-way communications transponder for relaying remote telemetry, sensor and user data for remote experimenters.
An intriguing little payload provided by students at Michigan Technological University seeks to permit detailed spectral analysis of spacecraft faces, shapes and overall “pose” as seen from ground stations, whilst the University of Texas at Austin’s Armadillo three-unit CubeSat will examine submillimetre particles of space debris and perform radio occultation experiments. The Planetary Society’s LightSail-B will be deployed from the Prox-1 nanosatellite and will itself deploy a suite of triangular sails, forming a diamond-like shape, not dissimilar to a huge Mylar kite. Orbiting at an altitude of 500 miles (800 km), LightSail aims to better understand the usefulness of sunlight as a propulsion source.
Earlier this spring, NASA outlined four of its own technology payloads which will fly as part of STP-2. These include a pair of CubeSat twins, dubbed the Enhanced Tandem Beacon Experiment (E-TBEx), which will participate in ongoing efforts to understand the day-to-day variability of space weather and the distortion of radio signals in the electrically-charged upper atmosphere. The Green Propellant Infusion Mission (GPIM) will evaluate the practical capabilities of a Hydroxyl Ammonium Nitrate fuel/oxidizer blend, which is low-toxicity and offers a greener, more high-performance alternative to hydrazine. Such propellants carry great promise to make spacecraft fueling safer, faster and less costly, as well as permitting a “shirt-sleeve” operational environment for ground processing.
The Deep Space Atomic Clock (DSAC)—the first-ever ion clock to fly in space, reportedly capable of taking nine million years to drift by a single second—will fly aboard the British-built Orbital Testbed (OTB) to validate miniaturized, ultra-precise, mercury-ion timing technology. It is described as several of magnitude more accurate and stable than any other space-flown atomic clock and carries potential to support autonomous navigation and exploration across deep space. The fourth and final NASA payload is the Space Environment Testbed (SET), which will evaluate ways of better guarding satellites against spaceflight-induced performance degradation.