Proceeding of the 6th International Symposium on Artificial Intelligence and Robotics & Automation in Space: i-SAIRAS 2001, Canadian Space Agency, St-Hubert, Quebec, Canada, June 18-22, 2001. Flight 6A: Deployment and Checkout of the Space Station Remote Manipulator System (SSRMS) Rod McGregor1 and Layi Oshinowo2 Canadian Space Agency 6767 Route de l’Aeroport, St-Hubert, Quebec, Canada, J3Y 8Y9 [email protected] [email protected] Keywords Activation, Canadarm2, Checkout, Deployment, Flight 6A, International Space 1.0 Introduction Station, ISS, Mobile Servicing System, MSS, Space Station Remote Manipulator System, The SSRMS was built for the Canadian Space SSRMS, STS-100. Agency (CSA) by MacDonald Dettwiler Space and Advanced Robotics (formerly Spar Abstract Aerospace) located in Brampton, Ontario. The SSRMS, or Canadarm2, is the principal Flight 6A of the International Space Station component of the MSS, Canada’s primary (ISS) assembly sequence, is currently completing hardware contribution to the International Space stage (shuttle departed) operations after its Station program. The Mobile Base System successful docked phase in April of this year. (MBS) and Special Purpose Dexterous This mission marks the delivery and checkout of Manipulator (SPDM) follow later on Flights UF- the first element of the Canadian Mobile 2 and UF-4 respectively. Delivery of the MSS Servicing System (MSS) – the Space Station components has been planned to progressively Remote Manipulator System (SSRMS). The expand the required robotic reach envelope for presence of this seven-jointed, re-locatable, and component installation and servicing, currently functionally-redundant robotic manipulator on- at the limit of the SRMS. orbit, with it’s larger reach and mass-handling The Canadarm2 was delivered to the ISS by the capacity, will allow for the expansion of the Space Shuttle Endeavor during the recently Station towards its assembly-complete form; completed Flight 6A mission. This paper is an beyond that which would be possible using only immediate post flight accounting of the primary the Shuttle Remote Manipulator System (SRMS) mission objectives of activation and checkout of a.k.a. the “Canadarm”. the SSRMS during docked operations. These In the immediate aftermath of the flight, the activities are described in four Phases. In Phase focus of this paper is to account the success of 1, initial activation required an initial EVA to the primary mission objectives of deployment route power and data cables to the Launch and checkout of the SSRMS. Operations are Deployment Assembly (LDA); the SSRMS described from removal of the folded SSRMS folded into a Space Lab Pallet (SLP), launch package from Space Shuttle Endeavor’s temporarily installed on the US Laboratory payload bay to it’s fully deployed configuration Module (US Lab) by the SRMS. In Phase 2 at the end of the docked (shuttle present) phase operations, commanded by the ISS crew from a of Flight 6A operations. Also discussed in the Robotic Workstation (RWS) in the US Lab, the paper are, from the SSRMS perspective, the SSRMS was maneuvered through a ‘step-off’ various extra-vehicular activity (EVA) and extra- sequence from the SLP to grapple the US Lab vehicular robotic (EVR) tasks executed to Power Data Grapple Fixture (PDGF) with it’s achieve these objectives, some of the mission Latching End Effector (LEE). For Phase 3, a constraints, and the operational processes and second EVA was performed to configure power products that are required for the success of and data connections to the US Lab PDGF, Flight 6A. which will serve at the SSRMS base for operations until the delivery of the MBS in early 2002. Finally, in a fourth Phase, the SLP was maneuvered by the SSRMS to a handoff position 1 Flight 6A Backup Lead, Space Operations Group, Canadian Space Agency (Calian Technologies Ltd). 2 Flight 6A Lead, Space Operations Group, Canadian Space Agency (MD-Robotics Ltd.). over to the SRMS, for return to the Shuttle 2.2 Launch Deployment Assembly payload bay. Various SSRMS On-orbit Checkout Prior to launch, the SSRMS was folded into a Requirements (OCRs) were integrated into the modified Space Lab Pallet (SLP) called the activation and deployment activities. The OCRs Launch Deployment Assembly (LDA) as shown and their pass/fail criteria were designed with the in Figure 1. The LDA served the following roles; near term objective of demonstrating required • Physical integration into the Orbiter payload functionality for ISS assembly operations bay as in Figure 3. starting with the Airlock installation on Flight • Structural attachment of SSRMS for Launch 7A in June 2001. Loads. • Unberth and installation interface to USLab 2.0 Hardware Description using Shuttle RMS. • EVA worksite. 2.1 The Space Station Remote Manipulator System (SSRMS) Eight, one meter long ‘Superbolts’ attach the SSRMS to the SLP for launch load restraint. The MSS equipment, operational capabilities, LEE A of the SSRMS is connected to an active modes and features have been described Flight Support Equipment Grapple Fixture extensively in the literature throughout its (FSEGF) which will supply power and data to development [1]. The SSRMS is 17 meters in the arm for initial deployment once connected by length, capable of maneuvering payloads up to EVA to the USLab. LEE B, the intended tip for the mass of the Space Shuttle itself. Seven joints initial deploy, is similarly restrained for launch are found on the shoulder and wrist clusters and by a passive (non-powered) FSEGF. The LDA is the mid-span elbow. These provide seven equipped with a Flight Releasable Grapple degrees of freedom, allowing infinite Fixture (FRGF) to allow the Shuttle RMS to configuration possibilities for any given position unberth, maneuver and install the LDA to the of the tip. The arm is symmetrical with two Lab LCA (Lab Cradle Assembly). The LDA has identical LEE’s, each able to serve as tip or base. the passive end of an LCA attachment The SSRMS has two functionally redundant mechanism, which is installed to the active LCA strings (power, data, electronics), allowing on the USLab. The total mass of the continued operations on the opposite string in the LDA/SSRMS assembly is 3050 kg. event of a fatal failure of a component. The Avionics (Arm Computer Unit, Video Distribution Unit) and LEEs, Joints and Cameras, as well as the two booms are all Orbital Replaceable Units (ORU’S) to facilitate on-orbit maintenance. The arm is commanded by the crew through one of two redundant Robotic Workstations, currently assembled in the USLab (Figure 7). The operator can manipulate the SSRMS through pre-programmed trajectories (automodes), or by manual control using translational and rotational handcontrollers. Manual modes can be single- joint operations where each joint is moved individually through a prescribed angle, and Figure 1: SSRMS on SLP, Launch Deploy Manual Augmented Mode (MAM), where the Assembly LEE tip, or any desired Point of Resolution (POR) is effectively ‘flown’ to a destination 2.3 USLab and Grapple Fixtures point through handcontroller input. Motion at the workstation is monitored by the operator (and The ISS USLab will be the base of operations for ground) by telemetry delivered to a Graphical the SSRMS over most of the next year. As of User Interface (GUI), and three monitors for Flight 5A.1, the lab was equipped with two video feeds routed from Orbiter, Station, or the RWS’s for human-in-the-loop command and arm itself. operation of the manipulator (see Figure 7). External to the lab are two grapple fixtures for Page 2 use by each end of the SSRMS. A standard The Checkouts planned for execution on the FRGF is to be captured by the SSRMS Tip LEE flight are listed in Table 1 in priority order with for structural support during long-term stowage. the associated Mandatory or Highly Desirable The Power Data Grapple Fixture (PDGF) has designation. The Mandatory SSRMS checkouts four receptacles which are mated to the Base are the highest 6A mission priority, after LEE Latches for Power/Data/Video connection Docking to ISS and SSRMS Activation / and structural / mechanical interface to the ISS Deployment. Checkout tasks designated as (Figure 2). Highly Desirable and some Desirable (not included with Table 1) are timelined for the mission, however remain subject to deferral in accordance with pre-set constraints. ‘Operational Pass’ criteria were pre-set with consideration to immediate mission objectives of readiness for cargo element manipulation. For this level, functionalities are evaluated against basic Go-no-Go criteria of expected GUI annunciation, and expected system performance as observed by crew and/or ground personnel at the Mission Evaluation Room (MER) in Houston and the Space Operations Support Center (SOSC) at CSA, St-Hubert. All data telemetry is Figure 2: Power Data Grapple Fixture downlinked to service the less immediate checkout objectives of commissioning, performance trending, and component 3.0 On-Orbit Checkout Requirements characterization. More than 50 individual functionality checkouts 4 SSRMS Activation and Checkout have been established for the SSRMS, with 40 tasks scheduled for 6A docked operations. Each 4.1 Phase 1: EVA Deploy, Powered Static of these tasks serves up to three objectives: Checkout, and Robotic Boom Raise 1. Establish equipment readiness for ISS Following a successful Launch on April 19, 2001 assembly operations (i.e. Flight 7A Airlock the Orbiter docked with the International Space installation) Station at 111/14:11:00 GMT. From the time of 2. Commissioning tests to confirm compliance docking to the ISS, thermal survival limits of to design specification. SSRMS components were limited to 68 hours 3. Data collection for on-orbit characterization without application of Keep Alive (KA) power. or performance trending / degradation monitoring. Tasks supporting the first objective have been designated as Mandatory checkouts for Flight 6A and Go Criteria for 7A launch.